Tray for water screens



May 23, 1933. w. w. sAYERs TRAY FOR WATER SCREENS 3 Sheets-Sheet l Filed Oct. 31

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May 23, 1933,. w, w. sAYERs TRAY.FOR WATER SCREENS 1930 5 Shes-Sheet 2 Filed Oct. 51

In we?? far' /Z May 23,v l933. w. w. sAYERs TRAY FOR WATER SCREENS Filed Oct. '51, 1950 '3 Sheets-Sheet 3 aff/a2?? ya Patented May 23, 1933 UNITED 4STATES PATENT OFFICE f WILLIAM W. sAYEmscr cIIICAGO, I LLINOIs, AssIeNon ro LINK BELT COMPANY, or

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS v TRAY FOR WATER SCREENS Application led October 31, 1930. Serial No. 492,483.

My inventionrelates to improvements in trays `for water screens and the like and has for one object, to provide a new and improved form of perforated rigid tray which will have a maximum of screen area and wherein total area of the screen panel.

the adjacent trays and their reinforcing and supporting flanges will not interfere with one another when the screen is cleaned by a water jet.

' 1'0"` It has in thepast been customary to make waterscreens built up of a plurality of rigid and get a larger screen area,but the leg or flanges ofthe topor bottom tray member projectingoutwardly from the screens will' interfere with the adjacent screen, form pocketsin which refuse material may be caught and will make it diflicult to direct the cleaning jet of water against the entire screen area. i n f f I propose, therefore, to arrange the top and bottom angles which form a part of the tray I frame in such wise that at the top'or instance, the leg extends inwardly and at the bottom it.` extends outwardly Or vice versa, thus the two legs may be placed inregister and a minimum of obstruction results.

l/Vater screens are ordinarily made of aV series of panels articulated and these panels are wider than they are high because their height is measured in the direction of screen or chain travel andV in that direction, the

height of the individual panel is ordinarily much less than the width of the screen made up by the panels. to the panels, l talk about the two long sides as top and bottom, the `two short sides as the sides and that part of the screen panel Therefore, in referring.

to still considerthat part which was orig` inally top as top and that part which was originally bottom, as bottom.

My invention is illustrated more or less diagrammaticall in the accompanying drawings, where1n Figure 1 is a diagrammatic section through a screen illustrating the application of my invention; n

Figure 2 is a section on a large scaleshowing in greater detail the screen trays and their relation with one another when refuse is sprayed oli in the ascending side; i i Figure 3 is a part plan View of Figure 2 showing one end of the screen tray and chain; i

Figure t is a section somewhat similar to Figure 2 showing a modified form of tray `with the top and bottom flanges projecting upwardlyinsteadoi downwardly.y as in Figure 2; i i

Figure 5 is a view of a screen similarto Figure l but showing the arrangement when the screen is cleaned or washed ou the descending instead of the ascend-ing run;

Figure 6 is a section along the line 6-6 of Figure 5;

Figure 7 shows a detail of a slightly further modified form.

Like parts are indicated by like characters throughout the specilication and drawings.

The screen comprises a supporting framework. A is a frame which rests in a wellA1L in a water conduit A2. `A3 is a tail sprocket, A4 a head sprocket. The motor A5 drives the head sprocket and the link chain AG travels over the head and tail sprocketsV up and down along the frame, one side oit' the chain, the side which is doing the screening beingr guided, supported, and protected in the tracks A7 in the frame, the other side hanging freely. At the upper end the head sprocket is enclosed in a housing A8 which also includes a sluice channel A.V A10 is a pipe having perforations adapted to discharge water against and through the screen cloth as they pass and to wash refuse oi the screen into the sluice A. The water to be screened travels in the direction of the arrow and in Figures 2 and 4 the refuse is washed f'flange B7 also extending unflanged, and plates or angles l built up of a plurality of articulated .links B.

The links carry side plates Bfwhich assist in preventing flow 'ofi refuse bearing water.

around the screen. Mounted between each pair of inside links is a tray B2. rIhe tray is built up of angles, the side members B3 having their bottom flanges extending inwardly, the top member B4 havings its bottom flange B5 extended downwardly and so inwardly. The bottom member B6 having its bottom downwardly and so outwardly.

The flange B7 projects outwardly from the frame and therefore does not obstruct the screening area, and as shown, the flange B7 masks theflange B5 and the top of the frame at B6 is practically in line with the top of B4 and so provides a smooth surface with the screen coming clear down to it and there permits the sprays to remove accumulated refuse ."from the screen cloth. VThe screen itself is indicated at B8 and is held on the flanges by means of holding strips B9 boltedy or riveted in place.

lVhen a jet of water is projected against i the back of the screen cloth by the spray pipe indicated diagrammatically at B10, it dislodges and washes the refuse off the screen cloth into the sluice trough. Any'refuse accumulated on top of BG will be washed in the .l sluice trough in passing the sprays. When the spray pipe B10 is in the dotted position with respect to the trays, it will be noted that the flange B7, being behind the flangeV B5, does not interfere with the spray water removing the refuse from the f'op'of B6, As the flange B5 is located at the top of the tray and as it travels upwardly, gravity prevent-s refuse from'being deposited upon it.

and therefore it is not necessary to wash. the

side to which they screen cloth is attached.

It will be noted that this water washing action is a positive and distinctly violent one. The wateris project-ed against the screen at high pressure, perhaps one hundred pounds or more and it washes and ects kthe Vrefuse violently off the screen discharging it into the solution. l

Referring now to Figure 5 here we have a traymade up of side plates Q which are U1 2 angle C1 having a downwardly extended bottom fla-nge C3, the lower angle C2 having a downwardly extended bottom flange C4 so that the flange C3 extends across a part of i the tray area to carry the screen cloth, which upperY is in this case fastened by means of a holding strip to the inside of the flange C3 and by a strip C5 to the outside of the flange C4. The ends of the screen are turned up to be fastened to the face of the plate C by a similar strip C6. This arrangement gives a maximum of screening area inside the tray. As the jet of cleaning water discharges against the back 'of the screen cloth from the position shown-at C7, the' water and refuse is removed from the cloth, and angles C2 and C1 and discharged. into the sliiice trough. vWith the jet of spray water discharging from the dotted position of C8, the flange C4 interferes no more than does the flange C3. Y

Referring to the arrangement shown in Figure 4, in this case the side and end frame arrangements are all flanged. The upper member D has a flange D1 extending upwardly away from the screen panel. The lower member D2 has a flange D3 extending upwardly away from the screen panel. The spray jet, washes the screen cloth B8 and discharges above the flanges D and D2. With the spray D7 discharging from the dotted position the same is true, the flanges D3 and D1 are in line and refuse which has accumulated on D2 will fall ofi' by gravity.

)In the device shown in Figure 7, it will be noted that in order to gain added space under some circumstances one of the transverse members, that is, one of the members extending perpendicular to the line of travel of the screen is bent into a position slightly inclined to the plane of the screen so that such member overlies to a greater or less extent the clamping area or clamping means. It will be noted here that the screen panel B8 is mounted on a flange E which flange is slightly inclined to the plane of the screen itself. The cross member upon which this flange is mounted at E1 is also slightly inclined to the perpendicular of the screen so that it lies behind the clamping member C3.

Attention is called to the fact that the spray nozzles D4 and C7. which are shown in dotted line position as D5 and C8 for the purpose of illustrating their operation, project or drive refuse material off the screen. the force with which the water strikes the cloth being sufficient to remove refuse and hurl it clear ofi' the sluice.

Bv the use of the word masks or masking in the claims, I have reference to one of the important characteristics of my invention which is that when viewing the screen in its screening position either from upstream or down, the parts are so positioned that the lower edge of one frame or panel masks or hides the upper edge of the one below. It is this masking effect which characterizes my invention and makes it possible to provide a submerged screen area whose effective height is such that it equals, not the total submerged height of the structure which is the ideal, not

ter of my application is used primarily fori preventing leaves, twigs, grass, llsh, etc., from passing the screen andreaching the condenser pumps or condensers where they are likely to either injure the pumps or greatly decrease the efliciency .of the condensers.

This type of screen is used primarily for screening the water passing to the condensers of a power house.

The water passes through the screen at a low velocity approximately two feet per second. Therefore, thereis ordinarily only a slight drop in the head of the water between the up side of the screen and that on the down f side or side near the condensers of the screen when the screen openings are not clogged by foreign substances. There is, however, a slight drop and it is extremely desirable to have the drop in head as, small as possible to cause the condenser pumps-touse as little power as possible in drawing the water through the screens.

With this background the desirability of providing screens with the greatest possible amount of net screening area for a given width and length of screen trays which make up the screening surface becomes most ap-` ging at times more or less solid material that accumulates at the bottom of the screen.

I claim:

1. A screen comprising a plurality of screen trays supported in articulated relation and so related that one tray may change its angular relation with respect to an adjacent tray without appreciable separation of the edges thereof, each tray having llanges approximately parallel with the axis about which it is articulated, the flanges in the plane of the screen portion of the tray on the opposed sides vof each tray projecting in the same direction, and means for mounting the trays in such articulated relation with the inwardly projecting flanges on each tra-y masking the outwardly projecting flanges of an adjacent tray when viewed in a direction perpendicular to the tray.

2. A screen comprising chains, a plurality of screen carrying trays supported by the chains in articulated relation and so disposed that travel of the chains and trays about a sprocket may take place without longitudinal separation of the trays, flanges on the sides of each tray perpendicular to the plane of the screen portion thereof, a flange on one side of the tray parallel with the plane of the screen portion thereof projecting toward the interior thereof, a flange on the other side of the tray parallel with the plane of the screen portion thereof projecting outwardly from the tray, a screen fabric mounted on the flanges, the relative positions of the flanges parallel with the plane of each tray being such that the outwardly projecting ange on one tray masks the inwardly projecting flange on an adjacent tray, the frame members being arranged generally side by side so as to form an unobstructed surface for outflow of material from the screen.

3. A water screen comprising a plurality of trays disposed along the length of the screen, each tray comprising a supporting framework and a pervious screen surface mounted thereon, means including the framework for` clamping the pervious screen surface in position, the trays being relatively associated so that the clamping means on one tray masks the clamping means on another tray to provide an increased effective screen area in the length of the screen.

4. A screen panel for water screens and the like comprising a rectangular frame member, the top and bottom sides of which are flanged in general parallelism with the Y vplane of the screen, one flange extending away from the frame, the other inwardly toward it, a screen panel mounted on the frame, one edge of the panel being mounted on the outside ofthe outwardly extending flange, the opposed edge of the panel being mounted on the inside of the inwardly eX- .tending flange, the other two sides of the screen at their edges extending generally perpendicular to the plane of the screen panel` mounted on the inside of the inwardly eX` tending flange.

Signed at Chicago, county of Cook, and State of Illinois, this l day of Aug., 1930.

WILLIAM W. SAYERS. 

